Question 1

Consider the following reaction at a certain temperature: 2HI(g)  →H2(g) + I2(g) K = 0.420
If 2.0 mol of H2(g) and I2(g) ,and 0.10 mol HI(g) were mixed in a 1.0-L flask,then

Accepted Answer

A)  the concentration of I2(g) would increase.
B)  the value of K would increase to 400.
C)  the concentration of HI(g) would increase.
D)  no change would occur.
E)  the total number of molecules would decrease.F) A) and C)
G) C) and E)

Question 2

The equilibrium constant,K,for the reaction 2HgO(s)  → 2Hg(l) + O2(g) 
Is 1.2 * 10-30.Calculate K for the reaction
1/2O2(g) + Hg(l)  → HgO(s) .

Accepted Answer

A)  -1.1 * 10-15 
B)  8.3 * 1029 
C)  4.2 * 1029 
D)  9.1 * 1014 
E)  1.1 * 10-15 F) A) and C)
G) C) and D)

Question 3

At the normal boiling point of chlorine,238.5 K,ΔH of vaporization is 20.4 kJ.mol-1.For the reversible vaporization of 1 mol of chlorine at 238.5 K and a constant pressure of 1 atm,determine q,ΔS,and ΔG.

Accepted Answer

20.4 kJ.mol^-1

Question 4

Consider the reaction 2HI(g)  →H2(g) + I2(g) 
At 298 K,Kc = 1.3 *10-3,whereas at 783 K,Kc = 2.2 * 10-2.Which of the following is true?

Accepted Answer

A)  The reaction is exothermic.
B)  The reaction is endothermic.
C)  At 298 K,K = 3.2 * 10-2.
D)  At 298 K,the reaction is likely to be spontaneous.
E)  At 783 K,more HI(g) is produced.F) A) and E)
G) B) and C)

Question 5

A mixture consisting of 0.250 M N2(g) and 0.500 M H2(g) reaches equilibrium according to the equation below: N2(g) 3H2(g)  → 2NH3(g) 
At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of N2(g) at equilibrium.

Accepted Answer

A)  0.150 M
B)  0.100 M
C)  0.0750 M
D)  0.0500 M
E)  0.175 MF) C) and D)
G) A) and E)

Question 6

For the equilibrium N2O4(g) →2NO2(g),plot,on the same graph,the forward and reverse reaction rates as a function of time.If possible,mark on the graph where equilibrium is reached.

Accepted Answer

Eventually the rate of the for...

Question 7

Consider the following reaction at a certain temperature: 
PCl5(g)  →PCl3(g) + Cl2(g) 
Kc = 0.100
At equilibrium,[PCl5] = 2.00 M and [PCl3] = [Cl2] = 1.00 M.If suddenly 1.00 M PCl5(g) ,PCl3(g) ,and Cl2(g) is added,what is the equilibrium concentration of Cl2(g) ?

Accepted Answer

A)  3.0 M
B)  essentially zero
C)  0.65 M
D)  2.75 M
E)  3.35 MF) A) and D)
G) C) and E)

Question 8

For the reaction 2NOCl(g) → 2NO(g)+ Cl2(g),if,initially,[NOCl(g)] = 2.8 M,at equilibrium [NO(g)] = 1.2 M.Calculate the equilibrium concentration of NOCl(g).

Accepted Answer

Question 9

A mixture consisting of 0.250 M N2(g) and 0.500 M H2(g) reaches equilibrium according to the equation below: N2(g) 3H2(g)  →2NH3(g) 
At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of H2(g) at equilibrium.

Accepted Answer

A)  0.0750 M
B)  0.350 M
C)  0.425 M
D)  0.275 M
E)  0.150 MF) B) and E)
G) C) and D)

Question 10

The equilibrium constant for the reaction
HNO2(aq)+ H2O(l) →NO2$\rightarrow$(aq)+ H3O+(aq)
is 4.3 * 10-4 at 25S1U1P1$\circ$S1S1P0C.Will nitrous acid spontaneously dissociate when
[HNO2(aq)] = [NO2-(aq)] = [H3O+(aq)] = 1.0 M? Show your calculations.

Accepted Answer

The answer of The equilibrium constant for the reaction
HNO2(aq)+ H2O(l)...

Question 11

Calculate the equilibrium constant for the following reaction at 25 ∘\circ∘ C 2TiCl3(s) + 2HCl(g)  → 2TiCl4(g) + H2(g) 
Given  Δ\DeltaΔ G ∘\circ∘  = +46.6 kJ.

Accepted Answer

A)  3.8 * 10-98 
B)  1.5* 10-19 
C)  6.7 * 10-9 
D)  6.6 * 1018 
E)  1.5 * 108  F) A) and B)
G) C) and D)

Question 12

Consider the reaction 
2CuBr2(s)  →\rightarrow→  2CuBr(s) + Br2(g) 
If the equilibrium vapor pressure of Br2(g) is 1.43 * 10-5 Torr at 298 K,what is  Δ\DeltaΔ G at this temperature when Br2(g) is produced at a pressure of 7.50 * 10-7 Torr?

Accepted Answer

A)  -7.31 kJ
B)  7.31 kJ
C)  39.9 kJ
D)  -3.17 kJ
E)  -4.15 kJ F) A) and B)
G) C) and E)

Question 13

At equilibrium,Q = K and $\Delta$G°r = 0.

Accepted Answer

A) True 
 B)False

Question 14

Calculate the vapor pressure of chloroform,CHCl3(l) ,at 25°C.The standard free energies of formation of CHCl3(l) and CHCl3(g) are -71.84 and -70.12 kJ.mol-1 at 25°C,respectively.

Accepted Answer

A)  0.499 atm
B)  0.000255 atm
C)  0.813 atm
D)  1.0 atm
E)  0.97 atmF) A) and B)
G) None of the above

Question 15

The equilibrium constant,Kc,for the reaction 2SO2(g) + O2(g)  →2SO3(g) 
Is 11.7 at 1100 K.A mixture of SO2,O2,and SO3,each with a concentration of 0.015 M,was introduced into a container at 1100 K.Which of the following is true?

Accepted Answer

A)  SO2(g) and O2(g) will be formed until equilibrium is reached.
B)  [SO3] = 0.045 M at equilibrium.
C)  [SO3] = 0.015 M at equilibrium.
D)  SO3(g) will be formed until equilibrium is reached.
E)  [SO3] = [SO2] = [O2] at equilibrium.F) B) and C)
G) A) and E)

Question 16

Consider the reaction
4NH3(g)+ 7O2(g) →2N2O4(g)+ 6H2O(g)
If,initially,[NH3(g)] = [O2(g)] = 3.60 M,at equilibrium,[N2O4(g)] = 0.60 M.Calculate the equilibrium concentrations of all other species.

Accepted Answer

[NH₃(g)] = 2.40 M,[O₂(...

Question 17

For the decomposition of ammonia to nitrogen and hydrogen,the equilibrium constant is 1.47 * 10-6 at 298 K.Calculate the temperature at which K = 0.0100.For this reaction, Δ\DeltaΔ H ∘\circ∘  = 92.38 kJ.mol-1.

Accepted Answer

A)  241 K
B)  332 K
C)  59 K
D)  390 K
E)  117 K F) C) and D)
G) C) and E)

Question 18

From a plot of Gibbs free energy versus progress of reaction,the sign of $\Delta$Gr at any point along the curve is given by the slope of the curve.

Accepted Answer

A) True 
 B)False

Question 19

What is the relationship between K and Kc for the reaction below? 
2HgO(s)  → 2Hg(l) + O2(g)

Accepted Answer

A)  Kc = (RT) 2K
B)  K = Kc 
C)  Kc = RTK
D)  K = RTKc 
E)  K = (RT) 2Kc F) B) and E)
G) D) and E)

Question 20

If the Ksp of AgI is 1.5 × 10-16 at 298 K,what is ΔGr° for the reaction of Ag+(aq) with I-(aq) under standard conditions at 298 K.

Accepted Answer

A)  -90.3 kJ.mol-1
B)  +90.3 kJ.mol-1
C)  0
D)  +7.57 kJ.mol-1
E)  -7.57 kJ.mol-1F) B) and E)
G) All of the above

Exam 11: Chemical Equilibria

For the decomposition of ammonia to nitrogen and hydrogen,the equilibrium constant is 1.47 * 10-6 at 298 K.Calculate the temperature at which K = 0.0100.For this reaction, Δ\DeltaΔ H ∘\circ∘ = 92.38 kJ.mol-1.

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Consider the following reaction at a certain temperature: PCl5(g) →PCl3(g) + Cl2(g) Kc = 0.100 At equilibrium,[PCl5] = 2.00 M and [PCl3] = [Cl2] = 1.00 M.If suddenly 1.00 M PCl5(g) ,PCl3(g) ,and Cl2(g) is added,what is the equilibrium concentration of Cl2(g) ?

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If the Ksp of AgI is 1.5 × 10-16 at 298 K,what is ΔGr° for the reaction of Ag+(aq) with I-(aq) under standard conditions at 298 K.

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The equilibrium constant,Kc,for the reaction 2SO2(g) + O2(g) →2SO3(g) Is 11.7 at 1100 K.A mixture of SO2,O2,and SO3,each with a concentration of 0.015 M,was introduced into a container at 1100 K.Which of the following is true?

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A mixture consisting of 0.250 M N2(g) and 0.500 M H2(g) reaches equilibrium according to the equation below: N2(g) 3H2(g) → 2NH3(g) At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of N2(g) at equilibrium.

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At equilibrium,Q = K and Δ\DeltaΔ G°r = 0.

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The equilibrium constant,K,for the reaction 2HgO(s) → 2Hg(l) + O2(g) Is 1.2 * 10-30.Calculate K for the reaction 1/2O2(g) + Hg(l) → HgO(s) .

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Consider the following reaction at a certain temperature: 2HI(g) →H2(g) + I2(g) K = 0.420 If 2.0 mol of H2(g) and I2(g) ,and 0.10 mol HI(g) were mixed in a 1.0-L flask,then

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Consider the reaction 2HI(g) →H2(g) + I2(g) At 298 K,Kc = 1.3 *10-3,whereas at 783 K,Kc = 2.2 * 10-2.Which of the following is true?

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Consider the reaction 4NH3(g)+ 7O2(g) →2N2O4(g)+ 6H2O(g) If,initially,[NH3(g)] = [O2(g)] = 3.60 M,at equilibrium,[N2O4(g)] = 0.60 M.Calculate the equilibrium concentrations of all other species.

Correct Answerverified[NH3(g)] = 2.40 M,[O2(...View AnswerShow Answer

A mixture consisting of 0.250 M N2(g) and 0.500 M H2(g) reaches equilibrium according to the equation below: N2(g) 3H2(g) →2NH3(g) At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of H2(g) at equilibrium.

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What is the relationship between K and Kc for the reaction below? 2HgO(s) → 2Hg(l) + O2(g)

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For the reaction 2NOCl(g) → 2NO(g)+ Cl2(g),if,initially,[NOCl(g)] = 2.8 M,at equilibrium [NO(g)] = 1.2 M.Calculate the equilibrium concentration of NOCl(g).

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Calculate the equilibrium constant for the following reaction at 25 ∘\circ∘ C 2TiCl3(s) + 2HCl(g) → 2TiCl4(g) + H2(g) Given Δ\DeltaΔ G ∘\circ∘ = +46.6 kJ.

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For the equilibrium N2O4(g) →2NO2(g),plot,on the same graph,the forward and reverse reaction rates as a function of time.If possible,mark on the graph where equilibrium is reached.

Correct AnswerverifiedEventually the rate of the for...View AnswerShow Answer

Calculate the vapor pressure of chloroform,CHCl3(l) ,at 25°C.The standard free energies of formation of CHCl3(l) and CHCl3(g) are -71.84 and -70.12 kJ.mol-1 at 25°C,respectively.

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At the normal boiling point of chlorine,238.5 K,ΔH of vaporization is 20.4 kJ.mol-1.For the reversible vaporization of 1 mol of chlorine at 238.5 K and a constant pressure of 1 atm,determine q,ΔS,and ΔG.

Correct Answerverified20.4 kJ.mol-1View AnswerShow Answer

From a plot of Gibbs free energy versus progress of reaction,the sign of Δ\DeltaΔ Gr at any point along the curve is given by the slope of the curve.

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Consider the reaction 2CuBr2(s) →\rightarrow→ 2CuBr(s) + Br2(g) If the equilibrium vapor pressure of Br2(g) is 1.43 * 10-5 Torr at 298 K,what is Δ\DeltaΔ G at this temperature when Br2(g) is produced at a pressure of 7.50 * 10-7 Torr?

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The equilibrium constant for the reaction HNO2(aq)+ H2O(l) →NO2 →\rightarrow→ (aq)+ H3O+(aq) is 4.3 * 10-4 at 25 ∘\circ∘ C.Will nitrous acid spontaneously dissociate when [HNO2(aq)] = [NO2-(aq)] = [H3O+(aq)] = 1.0 M? Show your calculations.

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For the decomposition of ammonia to nitrogen and hydrogen,the equilibrium constant is 1.47 * 10^-6 at 298 K.Calculate the temperature at which K = 0.0100.For this reaction, $\Delta$ H^$\circ$ = 92.38 kJ.mol^-1.

Correct Answer
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Consider the following reaction at a certain temperature: PCl₅(g) →PCl₃(g) + Cl₂(g) K_c = 0.100 At equilibrium,[PCl₅] = 2.00 M and [PCl₃] = [Cl₂] = 1.00 M.If suddenly 1.00 M PCl₅(g) ,PCl₃(g) ,and Cl₂(g) is added,what is the equilibrium concentration of Cl₂(g) ?

Correct Answer
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If the K_sp of AgI is 1.5 × 10^-16 at 298 K,what is ΔG_r° for the reaction of Ag⁺(aq) with I^-(aq) under standard conditions at 298 K.

Correct Answer
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The equilibrium constant,K_c,for the reaction 2SO₂(g) + O₂(g) →2SO₃(g) Is 11.7 at 1100 K.A mixture of SO₂,O₂,and SO₃,each with a concentration of 0.015 M,was introduced into a container at 1100 K.Which of the following is true?

Correct Answer
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A mixture consisting of 0.250 M N₂(g) and 0.500 M H₂(g) reaches equilibrium according to the equation below: N₂(g) 3H₂(g) → 2NH₃(g) At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of N₂(g) at equilibrium.

Correct Answer
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At equilibrium,Q = K and $\Delta$ G°_r = 0.

Correct Answer
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The equilibrium constant,K,for the reaction 2HgO(s) → 2Hg(l) + O₂(g) Is 1.2 * 10^-30.Calculate K for the reaction 1/2O₂(g) + Hg(l) → HgO(s) .

Correct Answer
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Consider the following reaction at a certain temperature: 2HI(g) →H₂(g) + I₂(g) K = 0.420 If 2.0 mol of H₂(g) and I₂(g) ,and 0.10 mol HI(g) were mixed in a 1.0-L flask,then

Correct Answer
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Consider the reaction 2HI(g) →H₂(g) + I₂(g) At 298 K,K_c = 1.3 10^-3,whereas at 783 K,K_c = 2.2 10^-2.Which of the following is true?

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Consider the reaction 4NH₃(g)+ 7O₂(g) →2N₂O₄(g)+ 6H₂O(g) If,initially,[NH₃(g)] = [O₂(g)] = 3.60 M,at equilibrium,[N₂O₄(g)] = 0.60 M.Calculate the equilibrium concentrations of all other species.

Correct Answer
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[NH₃(g)] = 2.40 M,[O₂(...
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A mixture consisting of 0.250 M N₂(g) and 0.500 M H₂(g) reaches equilibrium according to the equation below: N₂(g) 3H₂(g) →2NH₃(g) At equilibrium,the concentration of ammonia is 0.150 M.Calculate the concentration of H₂(g) at equilibrium.

Correct Answer
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What is the relationship between K and K_c for the reaction below? 2HgO(s) → 2Hg(l) + O₂(g)

Correct Answer
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For the reaction 2NOCl(g) → 2NO(g)+ Cl₂(g),if,initially,[NOCl(g)] = 2.8 M,at equilibrium [NO(g)] = 1.2 M.Calculate the equilibrium concentration of NOCl(g).

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Calculate the equilibrium constant for the following reaction at 25^$\circ$C 2TiCl₃(s) + 2HCl(g) → 2TiCl₄(g) + H₂(g) Given $\Delta$ G^$\circ$ = +46.6 kJ.

Correct Answer
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For the equilibrium N₂O₄(g) →2NO₂(g),plot,on the same graph,the forward and reverse reaction rates as a function of time.If possible,mark on the graph where equilibrium is reached.

Correct Answer
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Eventually the rate of the for...
View Answer

Calculate the vapor pressure of chloroform,CHCl₃(l) ,at 25°C.The standard free energies of formation of CHCl₃(l) and CHCl₃(g) are -71.84 and -70.12 kJ.mol^-1 at 25°C,respectively.

Correct Answer
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At the normal boiling point of chlorine,238.5 K,ΔH of vaporization is 20.4 kJ.mol^-1.For the reversible vaporization of 1 mol of chlorine at 238.5 K and a constant pressure of 1 atm,determine q,ΔS,and ΔG.

Correct Answer
verified
20.4 kJ.mol^{-1View Answer}

From a plot of Gibbs free energy versus progress of reaction,the sign of $\Delta$ G_r at any point along the curve is given by the slope of the curve.

Correct Answer
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Consider the reaction 2CuBr₂(s) $\rightarrow$ 2CuBr(s) + Br₂(g) If the equilibrium vapor pressure of Br₂(g) is 1.43 * 10^-5 Torr at 298 K,what is $\Delta$ G at this temperature when Br₂(g) is produced at a pressure of 7.50 * 10^-7 Torr?

Correct Answer
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The equilibrium constant for the reaction HNO₂(aq)+ H₂O(l) →NO₂ $\rightarrow$ (aq)+ H₃O⁺(aq) is 4.3 * 10^-4 at 25^$\circ$C.Will nitrous acid spontaneously dissociate when [HNO₂(aq)] = [NO₂-(aq)] = [H₃O⁺(aq)] = 1.0 M? Show your calculations.

Correct Answer
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